[Lldb-commits] [lldb] [lldb] Add RegisterContextPOSIXCore for RISC-V 64 (PR #93297)

Fri May 24 04:38:27 PDT 2024

llvmbot wrote:




@llvm/pr-subscribers-lldb

Author: Alexey Merzlyakov (AlexeyMerzlyakov)

<details>
<summary>Changes</summary>

The PR adds the support of CoreDump debugging for RISC-V 64. It implements new `RegisterContextCorePOSIX_riscv64` class.

Also, the contribution fixes `GetRegisterCount()` -> `GetRegisterSetCount()` misprint in `RegisterContextPOSIX_riscv64::GetRegisterSetCount()` method, which leaded to `set && "Register set should be valid."` assertion during `register info aX` command call.

The patch was tested (on coredumps generated for simple Integer/FP calculation code) for _cross x86_64 -> RISCV_ and _native RISCV_ LLDB builds. There were performed basic LLDB functionality tests, such as:

 - CoreDump file load
 - Backtrace / frames
 - GP/FP registers read/info/list
 - Basic switch between threads
 - Disassembler code
 - Memory regions read / display

---
Full diff: https://github.com/llvm/llvm-project/pull/93297.diff


5 Files Affected:

- (modified) lldb/source/Plugins/Process/Utility/RegisterContextPOSIX_riscv64.cpp (+1-1) 
- (modified) lldb/source/Plugins/Process/elf-core/CMakeLists.txt (+1) 
- (added) lldb/source/Plugins/Process/elf-core/RegisterContextPOSIXCore_riscv64.cpp (+84) 
- (added) lldb/source/Plugins/Process/elf-core/RegisterContextPOSIXCore_riscv64.h (+60) 
- (modified) lldb/source/Plugins/Process/elf-core/ThreadElfCore.cpp (+7-1) 


``````````diff

diff --git a/lldb/source/Plugins/Process/Utility/RegisterContextPOSIX_riscv64.cpp b/lldb/source/Plugins/Process/Utility/RegisterContextPOSIX_riscv64.cpp
index 1834a94dc0260..035ce00e11626 100644
--- a/lldb/source/Plugins/Process/Utility/RegisterContextPOSIX_riscv64.cpp
+++ b/lldb/source/Plugins/Process/Utility/RegisterContextPOSIX_riscv64.cpp
@@ -58,7 +58,7 @@ RegisterContextPOSIX_riscv64::GetRegisterInfoAtIndex(size_t reg) {
 }
 
 size_t RegisterContextPOSIX_riscv64::GetRegisterSetCount() {
-  return m_register_info_up->GetRegisterCount();
+  return m_register_info_up->GetRegisterSetCount();
 }
 
 const lldb_private::RegisterSet *
diff --git a/lldb/source/Plugins/Process/elf-core/CMakeLists.txt b/lldb/source/Plugins/Process/elf-core/CMakeLists.txt
index 8ddc671e3ae66..72925c835b5c8 100644
--- a/lldb/source/Plugins/Process/elf-core/CMakeLists.txt
+++ b/lldb/source/Plugins/Process/elf-core/CMakeLists.txt
@@ -9,6 +9,7 @@ add_lldb_library(lldbPluginProcessElfCore PLUGIN
   RegisterContextPOSIXCore_ppc64le.cpp
   RegisterContextPOSIXCore_s390x.cpp
   RegisterContextPOSIXCore_x86_64.cpp
+  RegisterContextPOSIXCore_riscv64.cpp
   RegisterUtilities.cpp
 
   LINK_LIBS
diff --git a/lldb/source/Plugins/Process/elf-core/RegisterContextPOSIXCore_riscv64.cpp b/lldb/source/Plugins/Process/elf-core/RegisterContextPOSIXCore_riscv64.cpp
new file mode 100644
index 0000000000000..b0fd065e7cc62
--- /dev/null
+++ b/lldb/source/Plugins/Process/elf-core/RegisterContextPOSIXCore_riscv64.cpp
@@ -0,0 +1,84 @@
+//===-- RegisterContextCorePOSIX_riscv64.cpp ------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "RegisterContextPOSIXCore_riscv64.h"
+
+#include "lldb/Utility/DataBufferHeap.h"
+
+using namespace lldb_private;
+
+std::unique_ptr<RegisterContextCorePOSIX_riscv64>
+RegisterContextCorePOSIX_riscv64::Create(
+    lldb_private::Thread &thread, const lldb_private::ArchSpec &arch,
+    const lldb_private::DataExtractor &gpregset,
+    llvm::ArrayRef<lldb_private::CoreNote> notes) {
+  Flags flags = 0;
+
+  auto register_info_up =
+      std::make_unique<RegisterInfoPOSIX_riscv64>(arch, flags);
+  return std::unique_ptr<RegisterContextCorePOSIX_riscv64>(
+      new RegisterContextCorePOSIX_riscv64(thread, std::move(register_info_up),
+                                           gpregset, notes));
+}
+
+RegisterContextCorePOSIX_riscv64::RegisterContextCorePOSIX_riscv64(
+    Thread &thread, std::unique_ptr<RegisterInfoPOSIX_riscv64> register_info,
+    const DataExtractor &gpregset, llvm::ArrayRef<CoreNote> notes)
+    : RegisterContextPOSIX_riscv64(thread, std::move(register_info)) {
+
+  m_gpr_buffer = std::make_shared<DataBufferHeap>(gpregset.GetDataStart(),
+                                                  gpregset.GetByteSize());
+  m_gpr.SetData(m_gpr_buffer);
+  m_gpr.SetByteOrder(gpregset.GetByteOrder());
+
+  ArchSpec arch = m_register_info_up->GetTargetArchitecture();
+  DataExtractor fpregset = getRegset(notes, arch.GetTriple(), FPR_Desc);
+  m_fpr_buffer = std::make_shared<DataBufferHeap>(fpregset.GetDataStart(),
+                                                  fpregset.GetByteSize());
+  m_fpr.SetData(m_fpr_buffer);
+  m_fpr.SetByteOrder(fpregset.GetByteOrder());
+}
+
+RegisterContextCorePOSIX_riscv64::~RegisterContextCorePOSIX_riscv64() = default;
+
+bool RegisterContextCorePOSIX_riscv64::ReadGPR() { return true; }
+
+bool RegisterContextCorePOSIX_riscv64::ReadFPR() { return true; }
+
+bool RegisterContextCorePOSIX_riscv64::WriteGPR() {
+  assert(0);
+  return false;
+}
+
+bool RegisterContextCorePOSIX_riscv64::WriteFPR() {
+  assert(0);
+  return false;
+}
+
+bool RegisterContextCorePOSIX_riscv64::ReadRegister(
+    const RegisterInfo *reg_info, RegisterValue &value) {
+  const uint8_t *src = nullptr;
+  lldb::offset_t offset = reg_info->byte_offset;
+
+  if (IsGPR(reg_info->kinds[lldb::eRegisterKindLLDB])) {
+    src = m_gpr.GetDataStart();
+  } else { // IsFPR
+    src = m_fpr.GetDataStart();
+    offset -= GetGPRSize();
+  }
+
+  Status error;
+  value.SetFromMemoryData(*reg_info, src + offset, reg_info->byte_size,
+                          lldb::eByteOrderLittle, error);
+  return error.Success();
+}
+
+bool RegisterContextCorePOSIX_riscv64::WriteRegister(
+    const RegisterInfo *reg_info, const RegisterValue &value) {
+  return false;
+}
diff --git a/lldb/source/Plugins/Process/elf-core/RegisterContextPOSIXCore_riscv64.h b/lldb/source/Plugins/Process/elf-core/RegisterContextPOSIXCore_riscv64.h
new file mode 100644
index 0000000000000..3cf9531df2c1d
--- /dev/null
+++ b/lldb/source/Plugins/Process/elf-core/RegisterContextPOSIXCore_riscv64.h
@@ -0,0 +1,60 @@
+//===-- RegisterContextPOSIXCore_riscv64.h ----------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLDB_SOURCE_PLUGINS_PROCESS_ELF_CORE_REGISTERCONTEXTPOSIXCORE_RISCV64_H
+#define LLDB_SOURCE_PLUGINS_PROCESS_ELF_CORE_REGISTERCONTEXTPOSIXCORE_RISCV64_H
+
+#include "Plugins/Process/Utility/RegisterContextPOSIX_riscv64.h"
+#include "Plugins/Process/Utility/RegisterInfoPOSIX_riscv64.h"
+
+#include "Plugins/Process/elf-core/RegisterUtilities.h"
+#include "lldb/Target/Thread.h"
+#include "lldb/Utility/DataExtractor.h"
+#include "lldb/Utility/RegisterValue.h"
+
+#include <memory>
+
+class RegisterContextCorePOSIX_riscv64 : public RegisterContextPOSIX_riscv64 {
+public:
+  static std::unique_ptr<RegisterContextCorePOSIX_riscv64>
+  Create(lldb_private::Thread &thread, const lldb_private::ArchSpec &arch,
+         const lldb_private::DataExtractor &gpregset,
+         llvm::ArrayRef<lldb_private::CoreNote> notes);
+
+  ~RegisterContextCorePOSIX_riscv64() override;
+
+  bool ReadRegister(const lldb_private::RegisterInfo *reg_info,
+                    lldb_private::RegisterValue &value) override;
+
+  bool WriteRegister(const lldb_private::RegisterInfo *reg_info,
+                     const lldb_private::RegisterValue &value) override;
+
+protected:
+  RegisterContextCorePOSIX_riscv64(
+      lldb_private::Thread &thread,
+      std::unique_ptr<RegisterInfoPOSIX_riscv64> register_info,
+      const lldb_private::DataExtractor &gpregset,
+      llvm::ArrayRef<lldb_private::CoreNote> notes);
+
+  bool ReadGPR() override;
+
+  bool ReadFPR() override;
+
+  bool WriteGPR() override;
+
+  bool WriteFPR() override;
+
+private:
+  lldb::DataBufferSP m_gpr_buffer;
+  lldb::DataBufferSP m_fpr_buffer;
+
+  lldb_private::DataExtractor m_gpr;
+  lldb_private::DataExtractor m_fpr;
+};
+
+#endif // LLDB_SOURCE_PLUGINS_PROCESS_ELF_CORE_REGISTERCONTEXTPOSIXCORE_RISCV64_H
diff --git a/lldb/source/Plugins/Process/elf-core/ThreadElfCore.cpp b/lldb/source/Plugins/Process/elf-core/ThreadElfCore.cpp
index 3ce2a4a5c3fa4..2a83163884e16 100644
--- a/lldb/source/Plugins/Process/elf-core/ThreadElfCore.cpp
+++ b/lldb/source/Plugins/Process/elf-core/ThreadElfCore.cpp
@@ -35,6 +35,7 @@
 #include "RegisterContextPOSIXCore_mips64.h"
 #include "RegisterContextPOSIXCore_powerpc.h"
 #include "RegisterContextPOSIXCore_ppc64le.h"
+#include "RegisterContextPOSIXCore_riscv64.h"
 #include "RegisterContextPOSIXCore_s390x.h"
 #include "RegisterContextPOSIXCore_x86_64.h"
 #include "ThreadElfCore.h"
@@ -168,7 +169,8 @@ ThreadElfCore::CreateRegisterContextForFrame(StackFrame *frame) {
     }
 
     if (!reg_interface && arch.GetMachine() != llvm::Triple::aarch64 &&
-        arch.GetMachine() != llvm::Triple::arm) {
+        arch.GetMachine() != llvm::Triple::arm &&
+        arch.GetMachine() != llvm::Triple::riscv64) {
       LLDB_LOGF(log, "elf-core::%s:: Architecture(%d) or OS(%d) not supported",
                 __FUNCTION__, arch.GetMachine(), arch.GetTriple().getOS());
       assert(false && "Architecture or OS not supported");
@@ -184,6 +186,10 @@ ThreadElfCore::CreateRegisterContextForFrame(StackFrame *frame) {
           *this, std::make_unique<RegisterInfoPOSIX_arm>(arch), m_gpregset_data,
           m_notes);
       break;
+    case llvm::Triple::riscv64:
+      m_thread_reg_ctx_sp = RegisterContextCorePOSIX_riscv64::Create(
+          *this, arch, m_gpregset_data, m_notes);
+      break;
     case llvm::Triple::mipsel:
     case llvm::Triple::mips:
       m_thread_reg_ctx_sp = std::make_shared<RegisterContextCorePOSIX_mips64>(

``````````

</details>


https://github.com/llvm/llvm-project/pull/93297
